Post on 29-Dec-2015
Components of Population Change
2.3
Recap
• Learning targets 2.1 and 2.2• Which measure of density is the best
indicator as to whether a country will have enough food to feed their people?– physiological
• Which measure of density would be the best indicator of a country’s level of development?– agricultural
Recap
• Computer lab activity– Population and migration
Terms/Concepts
• Natural Increase Rate (NIR)• Crude Birth Rate (CBR)• Crude Death Rate (CDR)
Population
• Why is it important to study?– 2 questions WHERE and WHY– 7 billion people alive, more than any
other time in history– Population increasing at faster rate than
ever in history– All global population growth is
concentrated in LDCs (more MDCs at 0 percent growth)
Population
• Demographics– Study of characteristics of the
population– Census statistics– Could be used in marketing, political
research and campaigning
Why does population growth vary among countries?
• What factors influence population growth – pair share– Amount of food– Birth / death rates– Life expectancy– Culture contraceptives – Others
Components of Population Change
• Depending upon births and deaths; populations can increase, decrease or stay constant
• 3 Indicators / Measures of Change– NIR– CBR– CDR
Natural Increase Rate
• Natural Increase Rate (NIR)– Percentage by which a population grows
in a year– Only uses birth and death rates–Migration excluded
(immigration/emigration)• Map: LDC vs. MDC– LDC = less developed country
(developing)– MDC = more developed country
• More then 97 percent of the natural increase is clustered in developing countries
Doubling Time
• Doubling time– Number of years needed to double a
population, assuming a constant rate of natural increase
– At a rate of 1.2% per year, world pop. would double in about 54 years
–With current rate global pop. = 24 billion by 2100
Crude Birth Rate
• Crude Birth Rate (CBR)– the total number of live births in a year
for every 1,000 people alive in society – Ex. A CBR of 20 means that for every
1,000 people in a country, 20 babies are born over a 1-year period
Crude Death Rate (CDR)
• Crude Death Rate- the total number of deaths in a year for every 1,000 people alive in the society
• NIR = CBR – CDR– Ex. 20 – 5 = 15 (1.5%)
CBR
CDR
Terms/Concepts
• Natural Increase Rate (NIR)• Crude Birth Rate (CBR)• Crude Death Rate (CDR)